A stimulant that affects kids and adults similarly, caffeine is naturally produced in the leaves and seeds of many plants. Caffeine is also made artificially and added to certain foods. Caffeine is defined as a drug because it stimulates the central nervous system. At lower levels, it can make people feel more alert and energetic.

Especially in young kids, it doesn't take a lot of caffeine to produce these effects.

Here are some other reasons to limit kids' caffeine consumption:

Kids often drink caffeine contained in regular soft drinks. Kids who consume one or more 12-ounce (355-milliliter) sweetened soft drink per day are 60% more likely to be obese.

Caffeinated beverages often contain empty calories (calories that don't provide any nutrients), and kids who fill up on them don't get the vitamins and minerals they need from healthy sources, putting them at risk for nutritional deficiencies. In particular, kids who drink too much soda (usually starting between the third and eighth grades) may miss getting the calcium they need from milk to build strong bones and teeth.

Drinking too many sweetened caffeinated drinks could lead to dental cavities (or caries) from the high sugar content and the erosion of tooth enamel from acidity. How can sodas cause that much damage to kids' teeth? Consider this: One 12-ounce (355-milliliter) nondiet, carbonated soft drink contains the equivalent of 10 teaspoons of sugar (49 milliliters), as well as 150 calories.

Caffeine is a diuretic that causes the body to eliminate water (through urinating), which may contribute to dehydration. Whether the amount of caffeine in beverages is enough to actually cause dehydration is not clear, however. It may depend on whether the person drinking the beverage is used to caffeine and how much caffeine was consumed that day. To be on the safe side, it's wise to avoid excessive caffeine consumption in hot weather, when kids need to replace water lost through sweating.

Abruptly stopping caffeine may cause withdrawal symptoms (headaches, muscle aches, temporary depression, and irritability), especially for those who are used to consuming a lot of it.

Caffeine can make heart problems or nervous disorders worse, and some kids might not know that they're at risk.

One thing that caffeine doesn't do is stunt growth. Although scientists once worried that caffeine could hurt growth, this isn't supported by research.

Foods and Beverages With Caffeine

Although kids get most of their caffeine from sodas, it's also found in coffee, tea, chocolate, coffee ice cream or frozen yogurt, as well as pain relievers and other over-the-counter medicines. Some parents may give their kids iced tea in place of soda, thinking that it's a better alternative. But iced tea can contain as much sugar and caffeine as soda.

Here's how some sources of caffeine compare:

Item

Amount of Item

Amount of Caffeine

Jolt soft drink

12 ounces

71.2 mg

Mountain Dew

12 ounces

55.0 mg

Coca-Cola

12 ounces

34.0 mg

Diet Coke

12 ounces

45.0 mg

Pepsi

12 ounces

38.0 mg

7-Up

12 ounces

0 mg

brewed coffee (drip method)

5 ounces

115 mg*

iced tea

12 ounces

70 mg*

dark chocolate

1 ounce

20 mg*

milk chocolate

1 ounce

6 mg*

cocoa beverage

5 ounces

4 mg*

chocolate milk beverage

8 ounces

5 mg*

cold relief medication

1 tablet

30 mg*

*average amount of caffeine

Sources: U.S. Food and Drug Administration and the National Soft Drink Association